\(d,\\ =\left(x^2+2xy+y^2\right)-25\\ =\left(x+y\right)^2-25\\ =\left(x+y+5\right)\left(x+y-5\right)\\ e,\\ =\left(a+b\right)^2-c\left(a+b\right)\\ =\left(a+b\right)\left(a+b-c\right)\\ f,\\ =\left(x^2-4y^2\right)-\left(2x+4y\right)\\ =\left(x-2y\right)\left(x+2y\right)-2\left(x+2y\right)\\ =\left(x+2y\right)\left(x-2y-2\right)\)